This invention is in the field of devices for protecting optical detectors against high-intensity optical radiation. Many such devices are known, and include such things as mechanical and electroptical shutters, various types of filters, and lately, nonlinear optical materials which absorb, scatter, or reflect (or all three) incident radiation above some threshold value. While all of these devices have certain advantages, they suffer from various disadvantages which make them impracticable or unusable for some types of threat radiations. With the advent of high-power pulsed lasers, mechanical shutters, because of their slow operation times with respect to the rise time of a laser pulse, are unacceptable protection devices. Moreover, such shutters are complex in that they, along with electro-optical shutters, require radiation sensing and shutter operation circuits, i.e., the shutters are active rather than passive. Although passive devices such as interference filters are inherently instantaneous, they are restricted to particular wavelengths or restricted wavebands and are sensitive to incident radiation angle. Nonlinear optical materials may be both fast-acting and wideband, but often have threshold levels too high to prevent damage to sensitive optical detectors. The instant invention overcomes these disadvantages; it is fast-acting, wideband, insensitive to incident radiation angle, has a low enough threshold level to prevent damage to sensitive optical detectors, and is self-healing (which some prior art devices are not).